Electric switch



G. LEDDICK Dec. 1s, 1923.

ELECTRIC SWITCH Filed April 25 1921 Inventor George I SddCK, by HS Attovhey.

Patented Dec. 18,1923,

UNITED STATES PATENT OFFICE...

GEOBGELEDDICK, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A. CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application led April 25, 1921. Serial No. 484,095.

To allwlwmtma concer/n:

Be it known tiat I, GEORGE Lannion, a citizen of the United States, residing at Schenectad in the county of Schenectady, State of Ndw York, have invented certain new and Vuseful Improvements in Electric Switches, of which the following is a speciN cation.

One of the objects of my invention is to provide a switch which shall have coinparatively few simple cheaply manufactured parts and which shall nevertheless be reliable and effective in operation.

Although not necessarily limited thereto, the invention has a particular application to combination start and stop push button switches for controlling the starting and stopping of electric motors.

In carrying the invention into eifect in one form, i provide a switch having three circuit terminals and two relatively movable switch members mounted in one of the terminals. The overlapping ends of the switch members are mounted on a pin in the said 'terminal and a spring is disposed on the pin to provide a resilient -mounting for the switch members. The spring biases the ove iapping ends of the switch members into engagement with the said terminal and also biases 'the switch members to predetermined positions with respect to each other and 'trie other circuit terminals. The par s of the switch mounted within a casing and push buttons extending through the casing are provided for the purpose of operating the switch members against the bias of the spring.

The various features of construction and rangement of the parts within the casing;

Fig. 2 is a cross-sectional view of Fig. 1 with the top coverin position; Fig. 3 is a perspective view showing the various parts of the switch mounted on an insulating base with the casing removed; and Fig. 4C is a very simplified diagram of a motor control system in which my improved switch is shown in simplified diagram. i

Referring to the figures, the switch mechanism is mounted upon an insulating base 10. Three circuit terminals 11, 12 and 13 respectively are secured to the base 10 in the positions shown. The two relatively movable switch members 14 and 15 are loosely mounted on a pinr 16 in the intermediate terminal 12. These switch members are oppositely disposed with respect to each other and are mounted in the intermediate termii nal 12 so thatv their overlapping ends are in lo engagement with each other. These overlapping ends are biased into engagement with each other and into electric conductive relation with respect to the iufitermet'.A nal 12 by means of the single which surrounds the pin 1t. .i member 14e is adapted to be normaliy u engagement with its corresponding terminai 11., the switch member bia ed by the spring 17 so as to neri;q maire engagement with the circuit 'ter nai he start push button through the cover of the casi t,

2O connected 'te the prsii its end mounted in a slot 'A member 14, 'thereby providing` operatin0f the switch member 141 from 'the outside of the casing. The stop push button 21 also extends through the cover of the casing and has a post 22 which has its end mounted in the switch member 15 for the purpose of operating this switch meinber from the outside of the casing. The casing 19 has an aperture 23 through which the conductors to be connected to the circuit terminals 11, 12 and 13 are adapted to ass. p As thus constructed and arranged and with the parts in the various positions' shown in the drawings, the operation of my invention is as follows Referring to Fig. 4, when the start push button 18 is depressed against the action of the spring 17 into engagement with the circuit terminal 11, the switch member 14 will pivot about lll vat

the pin 16 in the circuit terminal 12. The switch.' member 15 will be unatl'ected and will remain in its normal position. A circuit for the winding of the electromagnetic switch 24 will be completed from the supply conductor 25 through the intermediate terminal 12, the switch member 14, the circuit terminal 11, through the winding 'to ground, the other side ot the supply circuit. lhe electromagnetic switch 24 will thereby be energized to close, and in closing will close the auxiliary switch 26, thereby completing a maintaining circuit for the switch winding through the switch member 15. The start push button 18 can thereupon be released and the electromagnetic switch 2t will remain closed toconnect the motor 27 to the supply circuit. 1n order to deenergize the electromagnetic switch 24, and thereby stop the motor, the stop push button 21 will be depressed and thereby cause the switch member 15 to pivot about the pin 16 against the action 'of the spring 17. 'lhis will cause the switch member 15 to break engagement with 'the circuit terminal 13 and thereby open the maintaining ycircuit for the winding of the electromagnetic switch 2li. rllhis electromagnetic switch will thereupon be deenergized and will open, disconnecting the motor from the source of supply. When the push button 21 is released and the switch member 15 is caused to return to its normal position, the

arts will be in their original positions, and 1t will be necessary to again depress the push button 18 in order to restart the motor.

1t will be seen that my improved switch has a comparatively few parts, which can be very easily manufactured and that the switch can be quickl assembled. switch members 14 an 15' can be identical parts, thereby effecting a saving in the num ber of diii'erent arts whichneed be manu- Vfactured. It wi lal'so be observed that a terminal 13 be reversed, the switch will have` two normally open switch members. It will also be seen that the circuit terminals 11 and 13 are interchangeable with each other if desired, so that only one form of circuit terminal need be made for these two termi# nale. 1t will also be observed that in the form shown in the drawings in case both' The remesa push buttons arel depressed, the spring 17 is merely put' under strain but no circuit is established through. the switch.

ln accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which l now consider to represent the bestembodiment thereof, but

yl desire to have it understood that the apsaid ends of thel switch members for holding each of the switch members in a predetermined position with respect to the other switch member and for holding the said overlapping ends in engagement with the said terminal, a circuit terminal adapted to be engaged by the other end of one switch member, and a circuit terminal adapted to be engaged by the other end of the other switch member. i

2. The combination in an electric switch of a circuit terminal-having a pin, two re1- atively movable switch members having one end of each member mounted on the said pin, a spring cooperatin with the said ends of the switch. members igor biasing the same into engagementV with the said terminal, a circuit terminal adaptedsto be engaged by the other end'of one of said switch members, land a circuit terminal adapted to be engaged by the other end of the other of said switch members.

3. The combination in an electric switch of a circuit terminal, two relatively movable switch members having one end of each member pivotally mounted in the said terminal, a spring cooperatingwith the said ends of the switch members for biasing the same into engagement with the said terminal, a' circuit terminal adapted to be engaged by the other end oi one of the switch members, and a circuit terminal adapted to be engaged by the other end of the other switch member. A

4. The combination in an electric switch of a circuit terminal, two relatively movable switch members having one "end of each member' pivotally mounted in the said terminal, a spring` cooperating with the said ends of the' switch members` for biasing the same into engagement with the said ter-` minal, a. circuit terminal adapted to be ena gaged by the other end of one of the switch members, and a circuitV terminal adapted to be engaged by the other end of the other switch member.

. 5.1The combination in an electric switch of a circuit terminal having a pin, two relatively movable switch members having overlapping ends pivotally mounted on the said pin, a -spring surrounding the said pin, adapted to press on the said overlapping ends of the said Switch members `for biasing the same into engagement with the said terminal, a circuit terminal adapted to be engaged by the other end of one of said switch members, and a circuit terminal adapted to be engaged by the other end of the other switch member.

6. The combination in an electric switch of a circuit terminal, two relatively movable switch members having overlapping ends mounted in the said terminal, a spring for resiliently supporting the said switch members and tor biasing the same into engagement with the said terminal, a circuit terminal adapted to 'be engaged by the other end of one of said switch members, a circuit terminal adapted to be engaged by the other end of the other switch member, a casing for the switch, and a push button for each switch member extending through the casrg for operating its respective switch mem- 7 .The combination in an electric switch of a. circuit. terminal having a pin, two oppositely disposed relatively movable switch members having overlapping ends loosely mounted on the said pin, a spring surrounding the said pin adapted to press on the overlapping `ends of the switch members to bias the same into engagement with the said terminal, a circuit terminal adapted to be normally in engagement with the other end of one of said switch members, a circuit terminal adapted to be engaged by the other end of the other switch member, and normally out of engagement therewith, a casing forthe switch, and a push button for each switch member extending through the casing for operating its respective switch member against the bias of said spring.

In witness whereof, I have hereunto set my hand this 22nd day of April, 1921.

GEORGE LEDDICK. 

